Replacing multiple delimited blocks in sed

sed

Solution

Try following command. It reads the whole file in memory and do global substitutions for each pair of delimiters:

sed -e '
    :a
    $! { N; ba };
    s/#\([^#]*\)#/[\1]#/g; 
    s/<\([^>]*\)>/[\1]>/g; 
    s/|\([^|]*\)|/[\1]|/g
' infile

It yields:

[A fully emphasized line]#
A line with [emphasis inside]#.
[Several lines of
text
With emphasis]#
no emphasis
Line [with]# multiple [emphasis]#.
Line [with some ]> [text of]| [each type]#.

Problem

I have a body of text which contains groups delimited with <>,## or ||. The blocks never overlap, but may cross multiple lines, like so: ``` #A fully emphasized line# A line with #emphasis inside#. #Several lines of text With emphasis# no emphasis Line #with# multiple #emphasis#. Line <with some > |text of| #each type#. ``` I'm attempting to replace each pair of delimiters with [ and ] and put the final delimiter after the ]; for example the last line should be: ``` Line [with some ]> [text of]| [each type]#. ``` I have formed a sed script which will do the first part: ``` sed -e ':left s/[#|<]/[/; t right; n; b left :right s/[#|>]/]/; t left;n; b right' ``` But when I try to use & (or (..) + \1) to put the character back in like this: ``` sed -e ':left s/[#|<]/[/; t right; n; b left :right s/[#|>]/]&/; t left;n; b right' ``` I get the following: ``` [A fully emphasized line][ A line with ][emphasis inside][. ][Several lines of text With emphasis][ no emphasis Line ][with][ multiple ][emphasis][. Line [with some ]]]]]]> [text of[ [each type[. ``` I'm not sure what has gone wrong here though - it appears to be screwing with the pattern block in some way. I could replace it with three calls (hardcoded one per match type), but that seems excessive.

Original source